Athletes more Likely to Deal with Heart Issues in Old Age: Study

The competitive life of an athlete can be rewarding and adventurous. Yet the physical endurance needed to combat many feats of strength may also be exhausting on the heart, particularly over time.

Researchers from the University of Manchester have found that many athletes who compete in endurance marathons, triathlons and iron man challenges may be significantly more likely to deal with certain heart issues.

"The heart rate is set by the heart's pacemaker, but this is controlled by the nervous system. The 'vagal' nerves lower the heart rate and therefore it was assumed the low heart rate of athletes is the result of over activity of the vagal nerves," said first study author Dr. Alicia D'Souza of the university, via a press release. "But our research shows this is not the case. Actually the heart's pacemaker changes in response to training and in particular there is a decrease in an important pacemaker protein, known as HCN4, and this is responsible for the low heart rate."

Study findings debunked the theory that increased activity of the autonomic nervous system creates a reaction to endurance training. For instance, while the average healthy adult will have a resting heart rate between 60 to 100 beats per minutes, an endurance athlete may have 30 or less, with long breaks in between each.

Researchers hope further studies can explain how molecular changes found in the cardiac structures or the sinus node play a role in arrhythmias or heart rhythm disturbances.

"This study shows the heart's electrical wiring changes in mice that exercise for long periods, and these changes in heart rhythm are sustained afterwards," said researcher Jeremy Pearson, Associate Medical Director at the British Heart Foundation, via the release. "If the findings are reproduced in humans they could have implications for heart health in older athletes. But much more research is needed before we could draw that conclusion."

More information regarding the findings can be seen via the journal Nature Communications.